LOS ANGELES - Researchers say face masks can prevent the spread of COVID-19, but which type of mask is the most effective?While there are relatively few specific guidelines pertaining to mask materials and designs, a new study from Florida Atlantic University, titled “Physics of Fluids”, found which types of masks offer the best protection against the coronavirus.Researcher Siddhartha Verma and his team experimented with different choices in material and design to “determine how well face masks block droplets as they exit the mouth,” the study explained.“We tested actually three homemade masks and one off-the-shelf commercial mask,” Verma said.Using droplets that were coughed and sneezed out of a mannequin head, the group of researchers.